Feat/migrate chem

[droomelotdegendt]

Goal

Migrate function get_chem to new data warehouse 'W0002_10_Watina'.

Key changes

• New function build_chem_query to separate table connections from R business logic
• Change table name reference (DimTijd --> DimDatum)
• Swap the legacy precalculated table ssrs_StaalEN for the new dim table DimStaal (which has 2 columns for electroneutrality: StaalElnNbr and ENCalculated)

Open questions

• ENCalculated from DimStaal used for column elneutr, or should StaalElnNbr be used?
• Currently under investigation by team Databeheer: ChemVariable CondF has duplicated values (current quick fix solution: filter(.data$ChemVarWID != 24))
• The new DWH has one extra measurement for every location: Si. Was this intenionally filtered in the previous DWH? Is this data newly added?
• Why is the output different when conc_type = eq?

Migration checks

To verify the code changes, the DWH migration snapshots were compared before and after migration (see the testing README for more information). The output is a one-on-one match except for:

• duplicates for the ChemVariable CondF (filtered out by the quick fix solution)
• Extra row for the ChemVariable Si
• When param conc_type = eq, the output has different values for the ChemVariable Al, Mn, and P-PO4

Note: to only check the DWH query changes, look at feat(get_chem): migrate to new DWH 'W0002_10_WATINA' separately